Lithium ion battery is a preferred battery for portable electronic products. In general, a lithium battery generates electric power by a chemical reaction between electrodes of a battery cell and an electrolyte. However, if the battery cell is abnormally used (or overcharged), materials such as the electrolyte may be decomposed in the chemical reaction to produce a flammable gas (such as hydrogen, etc), and such gas may cause an increase of the internal pressure of a casing of the battery, and thus resulting in a deformation of the casing or even an explosion.
Therefore, it is a main subject of this disclosure to improve the safety of the battery cell and discharge the flammable gas from the battery to prevent the flammable gas from filling the battery cell and prevent explosions by installing an exhaust structure on the battery cell.
In view of the aforementioned problems of the prior art, the discloser of this disclosure based on years of experience in the related industry to conduct extensive researches and experiments, and finally provided a feasible solution to overcome the problems of the prior art.